1. Technical Field
The present invention relates to super-resolved optical imaging, more particularly to an optical imaging apparatus and an optical imaging method using the apparatus that enable selective measurement along the horizontal and depth directions of a specimen.
2. Description of the Related Art
Biotechnology is fast rising as a next-generation industry, and accordingly, various bio-imaging techniques are being developed in the field of measurement systems.
The total internal reflection (TIR) imaging technique is a method of exciting a fluorescent substance by using evanescent waves that are formed when light undergoes total reflection. As the evanescent waves are formed within several hundreds of nanometers from a surface, it is possible to selectively excite only the fluorescent substance within a particular range. Because of this property, total internal reflection imaging may be utilized to study interactions at a particular interface, such as at a cell membrane, etc.
A conventional TIR microscope may be structured to excite a fluorescent substance dyed with a specimen, by using evanescent waves localized along the depth direction that are created when an incident beam undergoes total reflection at the interface between the specimen and a substrate, and to detect the fluorescence signals emitted from the excited fluorescent substance and convert them into an image. However, with the conventional TIR microscope, it is difficult or impossible to detect molecules or molecule trajectories, etc., in the horizontal direction which are smaller than the resolution limit that can be calculated by Abbe's equation of diffraction. Thus, there is a need for a TIR microscope that not only provides a high resolution in the depth direction but also provides a high resolution in the horizontal direction. Also, the conventional TIR microscope may not be able to provide selective excitation within the same surface.